Wiper arm assembly having a locking catch and method of construction

ABSTRACT

A wiper arm assembly and method of assembly thereof includes a mounting head and a wiper arm configured for relative rotation during assembly from a disassembled position to a shipping position, wherein the wiper arm and mounting head are locked against rotation toward the disassembled position once in the shipping position. The mounting head and wiper arm have locking surfaces configured for locked engagement with one another while in the shipping position. The locking surfaces are brought into engagement with one another by a force imparted by a spring while rotating the mounting head relative to the wiper arm from the disassembled position toward the shipping position. When in the shipping position, the locking surfaces confront each other and prevent the mounting head and the wiper arm from rotating back toward the disassembled position from the shipping position.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 60/863,000, filed Oct. 26, 2006, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to wiper arm assemblies for vehicles,and more particularly to wiper arm assemblies having a mounting head forattachment to a vehicle and a wiper arm attached for articulationrelative to the mounting head, and methods of assembly thereof.

2. Related Art

Wiper arm assemblies for vehicles are known to have a wiper arm hingedfor articulation relative to a mounting head. The mounting headfacilitates attachment of the assembly to a surface on the vehicle sothat a wiper blade attached to the wiper arm is suitably positioned foroscillation against a window. The wiper arm and wiper blade attachedthereto can generally be articulated relative to the mounting head awayfrom the window to a service-up position to facilitate replacing thewiper blade.

It is known to manufacture wiper arm assemblies with the mounting headand wiper arm permanently fixed to one another by a staked pin or rivet.In this type of construction, the pin or rivet is assembled betweenaxially aligned openings in the mounting head and wiper arm, and thenthe pin or rivet is fixed therein to permanently couple the partstogether sot that they can not be taken apart thereafter. At some pointin assembly, one end of a coil spring is attached to the mounting head,and an opposite end of the coil spring is attached to the wiper arm. Theforce imparted by the coil spring maintains the wiper blade in wipingengagement with the window as the mounting head is oscillated by a drivemotor. The spring also allows the wiper arm to be articulated away fromthe window by manually lifting the wiper arm, such that the wiper bladecan be serviced, as necessary. Though this type of wiper arm assemblyworks well in use, it typically comes with increased cost inmanufacturing and assembly due to the added cost associated with the pinor rivet and the processes for permanently fixing the mounting head andwiper arm together.

It is also known to manufacture wiper arm assemblies with the mountinghead and wiper arm attached to one another such that they can bedisassembled from one another after being assembled in a “preassembled”position. A preassembled position is defined when the mounting head andwiper arm are attached together, but not yet assembled to a vehicle. Inone known construction, as disclosed in the prior art section of U.S.Pat. No. 6,553,608 (the '608 patent), the mounting head and wiper armare attached together under a preload of a tension spring, with an axleon one of the parts being received to form a hinged connection in anopen hub of the other part. Bearing surfaces on the mounting head andwiper arm are pulled into engagement with one another along a line offorce imparted by the tension spring. The opposing reaction forcesbetween the bearing surfaces act to maintain the mounting head and wiperarm in the preassembled position until the wiper arm assembly is fullyassembled to a vehicle. Unfortunately, the bearing surfaces are notprevented from moving back toward a disassembled direction and can sliderelative to one another under a minimal force, which can occur duringtransport or during careless handling, whereupon the mounting head andwiper arm can become inadvertently disassembled.

To combat the problem of inadvertent disassembly set out in the priorart section of the '608 patent, the '608 patent teaches forming thebearing surfaces as being arranged to define interacting cammingsurfaces. In order for the mounting head and wiper arm to bedisassembled from their preassembled position, the bearing surfacesrequire the spring attaching the mounting head and the wiper arm to beincreased in length, thus requiring an increased tensile force to beovercome prior to the parts becoming disassembled from one another. Uponthe bearing surfaces overcoming a cam lobe, the point at which thetensile spring is at its greatest length, the length of the spring isallowed to decrease, thereby causing a tensile force imparted by thespring to disassemble the mounting head and the wiper arm from oneanother. Accordingly, the '608 patent teaches that the mounting head canstill be disassembled from the wiper arm by rotating the wiper armrelative to the mounting head toward the disassembled direction with asufficient torque to overcome the cam lobe.

SUMMARY OF THE INVENTION

A wiper arm assembly has a mounting head and a wiper arm for relativerotation therewith, wherein the wiper arm and mounting head are lockedagainst disassembly upon be assembled to a shipping position. Themounting head has one of an axle or a hub, while the wiper arm has theother of the axle or hub, wherein the hub has a pocket with an open endfor receipt of the axle for oscillation therein. The mounting head hasone end configured for attachment to a vehicle and an opposite end witha first locking surface extending therefrom. The wiper arm has oppositesidewalls with a second locking surface extending laterally outwardlyfrom at least one of the sidewalls. A spring is arranged for operableattachment to the mounting head and the wiper arm. The locking surfaceon the wiper arm is configured for engagement with the locking surfaceon the mounting head under a force imparted by the spring while rotatingthe mounting head relative to the wiper arm from a disassembled positiontoward a shipping position. The locking surfaces confront each otherwhile in the shipping position and prevent the mounting head and saidwiper arm from rotating back toward the disassembled position from theshipping position.

Another aspect of the invention provides a method of assembling a wiperarm assembly. The method starts with providing a mounting head and awiper arm. The mounting head is provided having one of an axle or a hub,with the hub be configured with an open pocket for receipt of the axlefor rotation therein. The mounting head is further provided with one endconfigured for attachment to a vehicle and an opposite end having afirst locking surface extending therefrom. The wiper arm is providedhaving the other of the axle or hub and having opposite sidewalls with asecond locking surface extending laterally outwardly from at least oneof the sidewalls. Then, attaching a spring to the mounting head and thewiper arm, and rotating the mounting head and the wiper arm relative toone another from a disassembled position toward a shipping position andcausing the spring to initially increase in preload and the axle to bereceived in said hub. Next, snapping the locking surfaces on themounting head and the wiper arm into engagement with one another andinto the shipping position under a force imparted by the spring duringthe rotating step, whereupon the locking surfaces prevent the mountinghead and the wiper arm from rotating back toward the disassembledposition.

According to yet another aspect of the invention, another method ofassembling a wiper arm assembly from a disassembled position to ashipping position is provided. The method includes providing a wiper armhaving a locking surface; a mounting head having a locking surface and aspring. Then, attaching the spring to the wiper arm and the mountinghead and imparting a preload in the spring by rotating the wiper arm andthe mounting head relative to one another. Next, bringing the lockingsurfaces of the wiper arm and the mounting head into snapping engagementwith one another under the preload of the spring, wherein the preloadmaintains the locking surfaces in confronting abutment with one anotherwhile in the shipping position and prevents the wiper arm and themounting head from being rotated back toward the disassembled position.

Accordingly, a wiper arm assembly constructed in accordance with theinvention, by way of example and without limitation, provides a wiperarm assembly that is easy to assemble, is economical in manufacture, isprevented from becoming disassembled during unintended relative rotationbetween the mounting head and wiper arm, and has a long and useful life.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of the presentinvention will become readily appreciated when considered in connectionwith the following detailed description of presently preferredembodiments and best mode, appended claims and accompanying drawings, inwhich:

FIG. 1 is a side view of a wiper arm assembly constructed according toone presently preferred embodiment of the invention shown in a shippingposition;

FIG. 2 is a side view of the wiper arm assembly shown in a disassembledposition;

FIG. 3 is a side view of the wiper arm assembly shown in a partiallyassembled position between the disassembled and shipping positions;

FIG. 4 is a side view of the wiper arm assembly shown just prior tosnapping into the shipping position;

FIG. 5 is a side view of the wiper arm assembly shown in a service-upposition;

FIG. 6 is a bottom view of the wiper arm assembly with a spring removed;

FIG. 7 is a partial cross-sectional view taken generally along a centralaxis of the wiper arm assembly while in the shipping position;

FIG. 8 is a view similar to FIG. 7 while in the disassembled position;

FIG. 9 is a view similar to FIG. 7 while in the partially assembledposition;

FIG. 10 is a view similar to FIG. 7 while in the service-up position;

FIG. 11 is a perspective view of a mounting head of the wiper armassembly;

FIG. 12 is a perspective view of a wiper arm of the wiper arm assembly;

FIG. 13 is an end view of the wiper arm;

FIG. 14 is a cross-sectional view taken generally along a central axisof a wiper arm assembly constructed in accordance with anotherembodiment of the invention; and

FIG. 15 is a side view of a wiper arm assembly constructed in accordancewith yet another alternate embodiment of the invention.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS

Referring in more detail to the drawings, FIGS. 1-6 show a wiper armassembly 10 constructed according to one presently preferred embodimentof the invention. The wiper arm assembly 10 has a mounting head 12 tofacilitate attachment of the assembly 10 to a vehicle, and a wiper arm14 for operable attachment of a wiper blade (not shown) to the assembly10. The wiper arm 14 is attached for articulated movement to themounting head 12 via a hinged joint 16 so that the wiper arm 14 can bepivoted in use and during assembly to a vehicle between a preassembledor shipping position (FIGS. 1 and 7) and a fully assembled position (notshown), wherein the assembly 10 is mounted to a vehicle. While in theshipping position, a locking mechanism 18 acts between the mounting head12 and wiper arm 14 to prevent them from being pivoted from the shippingposition back toward a disassembled position (FIGS. 2 and 8).Accordingly, the wiper arm assembly 10 is prevented from becominginadvertently disassembled, such as during shipping or while beinghandled prior to being attached to the vehicle.

As best shown in FIG. 11, the mounting head 12 extends between oppositeends 23, 25 and has a mounting portion 20 adjacent the end 23 and ahinge portion 22 adjacent the end 25. The mounting portion 20 preferablyhas an opening 24 to facilitate attachment of the assembly 10 to thevehicle via a standard fastener. The hinge portion 22 is configured toallow the wiper arm 14 to articulate relative to the mounting head 12.The mounting head 12 has a pair of laterally spaced sidewalls 26, 27defining a generally open channel 28 therebetween. An axle 30 of apredetermined diameter extends between the sidewalls 26, 27. The axle 30preferably defines a generally cylindrical bearing surface 31 facing theend 25 and being spaced a predetermined distance from the end 25. Themounting head 12 has a spring attachment feature, represented here, byway of example and without limitations, as a spring pin 32, extendingbetween the sidewalls 26, 27. To further define the attachment feature,a through opening 34 is preferably formed adjacent the spring pin 32.The spring pin 32 is located generally between the axle 30 and themounting portion 20. The mounting head 12 preferably has at least one,and shown here as a pair of stop surfaces 36 (FIG. 7-11) arranged tolimit the degree of pivot of the wiper arm 14 upwardly from the mountinghead, from the fully assembled position while on the vehicle to theservice-up position (FIGS. 5 and 10). It should be recognized that thedegree of movement between the assembled position and the service-upposition can be varied, as desired, by altering the stop surfaces 36.

As shown in FIG. 11, the locking mechanism 18 is defined in part on themounting head 12 by at least one, and shown here as a pair ofprotrusions, referred to hereafter as locking catches 38, extending fromthe ends 25 of the sidewalls 26, 27 and generally coplanar theretoadjacent bottom surfaces 40 of the sidewalls 26, 27. The bottom surfaces40 are preferably substantially flat or planar for mounting engagementwith a vehicle surface, although they could be formed having anysuitable surface contour. The locking catches 38 have generally flatlocking surfaces 42 provided in part by generally flat recessed surfaces44 extending into the ends 25 of the sidewalls 26, 27. The lockingsurfaces 42 are represented here, by way of example and withoutlimitation, as being substantially perpendicular to the recessedsurfaces 44 and substantially parallel to the bottom surfaces 40.

As best shown in FIG. 12, the wiper arm 14 has an elongate bodyextending longitudinally between opposite ends 46, 48, with one end 46,for example, being configured for attachment to the wiper blade, and theother end 48 being configured for pivotal attachment to the mountinghead 12. To facilitate operable attachment of the wiper arm 14 to themounting head 12, the wiper arm 14 has a spring attachment feature,shown here as a spring hook 53 (FIGS. 6-10), attached to a bottom orunderside surface of the wiper arm 14, wherein the spring hook 53 can beformed as a single piece of material with the wiper arm 14, such as in amolding process, for example.

The end 48 of the wiper arm has a pair of sidewalls 47, 49 laterallyspaced from one another with a centrally extending spring channel 55located between the sidewalls 47, 49. The sidewalls 47, 49 have outersurfaces arranged for close receipt within the hinge portion 22 of themounting head 12 between its laterally spaced sidewalls 26, 27. Tominimize friction in use, the sidewalls 47, 49 can have protrusionsextending outwardly therefrom a predetermined distance, representedhere, by way of example and without limitation, as longitudinal ribs 51extending generally along a length direction of the sidewalls 47, 49.

The end 48 of the wiper arm is shown as having a hub 50, preferablyformed as a monolithic piece of material with the wiper arm 14, althoughit could be formed as a separate piece and attached thereafter. The hub50 has a pocket 52 extending into the end 48 of the wiper arm 14 apredetermined distance along the length of the hub 50 to a closedseating surface 54. The pocket 52 and opening formed at the end 48 ispreferably sized for close receipt of the axle 30, such that the axle 30is free to oscillate within the pocket 52. The seating surface 54 can beformed having a generally cylindrical or constant radius, concavecontour to conform generally to the convex cylindrical bearing surface31 on the axle 30. At least one, and preferably a pair of lockingfeatures, represented here by protrusions 56, for example, extendlaterally away or outwardly from the sidewalls 47, 49, wherein theprotrusions 56 can be attached to or spaced from the sidewalls 47, 49.The protrusions 56 have front abutting surfaces, referred to hereafteras front surfaces 58 facing the end 48 for abutment with the lockingcatches 38 during assembly and lower locking surfaces, referred tohereafter as stop surfaces 60, configured for mating, confrontingengagement with the locking surfaces 42 on the mounting head 12. Thefront surfaces 58 and stop surfaces 60 are shown here as being generallyperpendicular to one another.

To assemble the mounting head 12 to the wiper arm 14, a spring, shownhere as a coil spring 62, is attached and tensioned between the mountinghead 12 and the wiper arm 14. To facilitate attachment of the coilspring 62 to the respective attachment locations on the mounting head 12and wiper arm 14, the coil spring 62 has hooked, generally c-shapedopposite ends 64, 65, with one end 64 being attached to the spring pin32 of the mounting head 12 and the other end 65 being attached to thespring hook 53 of the wiper arm 14. Upon first attaching the coil spring62, the wiper arm assembly 10 is in its disassembled position (FIGS. 2and 8) and the axle 30, which is located between the locking surface 42and the end 20, is preferably placed in abutting contact with the end 48of the wiper arm 14 adjacent the pocket 52 of the hub 50. While in thedisassembled position, the wiper arm assembly 10 is able to be readilytaken apart, and can generally fall apart if not handled properly.

To proceed in assembly, the mounting head 12 and wiper arm 14 arerotated relative to one another, with the mounting head 12 being movedcounter clockwise, as viewed in FIGS. 3 and 9, wherein the mounting head12 and wiper arm 14 are shown in a partially assembled position. In thisposition, the axle 30, which is located between the locking surfaces 42and the end 23, begins to enter the pocket 52, and the coil spring 62 isincreased in length, thus, increasing the tension force in the spring62. The mounting head 12 and wiper arm 14 are rotated further inassembly and the axle 30 is received in the pocket 52 so that thetension imparted by the coil spring 62 pulls or biases the axle 30toward the seating surface 54. The locking catches 38 first abut thefront surfaces 58 of the protrusions 56 (FIG. 4), and the axle 30remains spaced from the seating surface 54 and the locking surfaces 42,60 remain out of engagement with one another. Accordingly, in thisposition, the assembly can still be freely rotated back toward thedisassembled position, if desired. As the mounting head 12 and wiper arm14 are rotated further relative to each other, the locking catches 38clear the respective front surfaces 58 and snap toward the wiper arm 14under the tension and bias of the coil spring 62 (FIG. 1). Accordingly,the tension in the coil spring 62 decreases, since the length betweenits ends is decreased, and the assembly is brought into the shippingposition. With the wiper arm assembly 10 now in the shipping position,the recessed surfaces 44 on the mounting head 12 can be configured toengage the front surfaces 58 on the protrusions 56, and the lockingsurfaces 42 on the mounting head 12 engage the stop surfaces 60 on theprotrusions 56. Accordingly, the mounting head 12 and the wiper arm 14are prevented from being rotated back toward the disassembled positionby the respective locking and stop surfaces 42, 60. Therefore, once inthe shipping position, the wiper arm assembly 10 is generally lockedagainst disassembly without the aid of tools. When the wiper arm 14 isassembled in the shipping position, the bearing surface 31 of the axle30 can be configured to seat against the seating surface 54 while thelocking mechanism 18 is engaged, though it is possible that a slight gapcould be present.

As shown in FIG. 5, when the wiper arm assembly 10 is assembled to thevehicle, the wiper arm 14 can be rotated further in a counter clockwisedirection (the same direction of rotation used to assembly the mountinghead 12 to the wiper arm 14) relative to the mount head 12 into theservice-up position. During rotation toward the service-up position, theaxle 30 preferably remains seated against the seating surface 54. Whilein the service-up position, the wiper arm 14, and thus, the wiper bladeare moved away from the vehicle window.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. For example, as shown inFIG. 14, it should be recognized that the axle 30 and the hub 50 couldbe constructed in the reverse orientation. Accordingly, an axle 130could be attached to a wiper arm 114, and a hub 150 could be formed orattached on a mount head 112. Similarly, as shown in FIG. 15, thestructure of the locking mechanism 18 could be reversed. Accordingly, alocking catch 238 could be attached on a wiper arm 214, and protrusions256 and associated stop surfaces 260 could be attached to a mount head212. It is, therefore, to be understood that within the scope of theappended claims, and any other claims allowed which stem from thisapplication, that the invention may be practiced otherwise than asspecifically described and shown.

1. A wiper arm assembly, comprising: a mounting head having one of anaxle or a hub, said hub comprising an open pocket for receipt of saidaxle for rotation therein, said mounting head having one end configuredfor attachment to a vehicle and an opposite end having a first lockingsurface extending therefrom; a wiper arm having the other of said axleor hub and having opposite sidewalls with a second locking surfaceextending laterally outwardly from at least one of said sidewalls; aspring configured for operable attachment to said mounting head and saidwiper arm; and said locking surface on said wiper arm being configuredfor engagement with said locking surface on said mounting head under aforce imparted by said spring while rotating said mounting head relativeto said wiper arm from a disassembled position toward a shippingposition, said locking surfaces confronting each other while in saidshipping position and preventing said mounting head and said wiper armfrom rotating back toward said disassembled position from said shippingposition.
 2. The wiper arm assembly of claim 1 wherein said mountinghead has a pair of said first locking surfaces spaced laterally from oneanother and said wiper arm has a pair of said second locking surfacesspaced laterally from one another.
 3. The wiper arm assembly of claim 1wherein said axle is attached to said hub.
 4. The wiper arm assembly ofclaim 3 wherein said axle is located between said first locking surfaceand said one end.
 5. The wiper arm assembly of claim 1 wherein saidmounting head has opposite sidewalls extending to said opposite endhaving said first locking surface, said first locking surface beingprovided by a recess extending into at least one of said mounting headsidewalls.
 6. The wiper arm assembly of claim 5 each of said mountinghead sidewalls has one of said recess to provide a pair of said lockingsurfaces.
 7. The wiper arm assembly of claim 5 wherein said firstlocking surface is coplanar with a respective one of said sidewalls. 8.The wiper arm assembly of claim 5 wherein said sidewalls haveprotrusions extending outwardly therefrom.
 9. The wiper arm assembly ofclaim 8 wherein said protrusions are formed as longitudinally extendingribs.
 10. The wiper arm assembly of claim 1 wherein said mounting headhas a stop surface configured to abut said wiper arm to limit therelative rotation of said mounting head and said wiper arm beyond saidshipping position.
 11. A method of assembling a wiper arm assembly,comprising the steps of: providing a mounting head having one of an axleor a hub, said hub comprising an open pocket for receipt of said axlefor rotation therein, said mounting head having one end configured forattachment to a vehicle and an opposite end having a first lockingsurface extending therefrom; providing a wiper arm having the other ofthe axle or hub and having opposite sidewalls with a second lockingsurface extending laterally outwardly from at least one of saidsidewalls; attaching a spring to said mounting head and said wiper arm;rotating said mounting head and said wiper arm relative to one anotherfrom a disassembled position toward a shipping position and causing saidspring to initially increase in preload and said axle to be received insaid hub; and snapping said locking surfaces on said mounting head andsaid wiper arm into engagement with one another and into said shippingposition under a force imparted by said spring during said rotatingstep, said locking surfaces preventing said mounting head and said wiperarm from rotating back toward said disassembled position.
 12. The methodof claim 11 further including providing said wiper arm with said hub andsaid mounting head with said axle.
 13. The method of claim 12 furtherincluding providing said mounting head with opposite sidewalls with eachof said sidewalls having a separate one of said first locking surfaceextending therefrom.
 14. The method of claim 12 further includingproviding said wiper arm with protrusions extending away from saidsidewalls, said protrusions providing said locking surfaces along onesurface of said protrusions and providing front abutment surfaces alonganother surface of said protrusions.
 15. The method of claim 14 furtherincluding configuring said locking surfaces of said protrusionsgenerally perpendicular to said front abutment surfaces of saidprotrusions.
 16. The method of claim 14 further including providing saidmounting head with a mounting bottom surface and configuring saidlocking surfaces to face toward said mounting bottom surface andconfiguring said abutment surfaces to face toward said one end.
 17. Amethod of assembling a wiper arm assembly from a disassembled positionto a shipping position, comprising the steps of: providing a wiper armhaving a locking surface, a mounting head having a locking surface and aspring; attaching the spring to said wiper arm and said mounting head;imparting a preload in said spring by rotating said wiper arm and saidmounting head relative to one another; and bringing said lockingsurfaces of said wiper arm and said mounting head into snappingengagement with one another under said preload of said spring, saidpreload maintaining said locking surfaces in confronting abutment withone another while in said shipping position and preventing said wiperarm and said mounting head from being rotated back toward saiddisassembled position.
 18. The method of claim 17 further includingproviding said mounting head with one of a hub or an axle, said hubhaving a pocket extending from an open end configured to receive saidaxle to a seating surface, and providing said wiper arm with the otherof said hub or said axle.
 19. The method of claim 18 further includingproviding said wiper arm with said hub and said mounting head with saidaxle.
 20. The method of claim 18 further including configuring one endof said mounting head for attachment to a vehicle and providing saidlocking surface of said mounting head at an end opposite to said oneend.
 21. The method of claim 17 further including providing saidmounting head with a substantially planar bottom surface for mountingengagement on a vehicle and configuring said locking surface on saidmounting head to be substantially parallel to said bottom surface. 22.The method of claim 17 further including preventing relative rotationalmovement between mounting head and said wiper arm from said shippingposition back toward said disassembled position in the absence of lineartranslation of said mounting head from said wiper arm.